Dr. Brendan Barrett in the Dialysis
Unit at the Health Sciences Centre.

A national pilot study on moderately advanced
kidney disease and its associated heart and blood vessel problems
is being coordinated at Memorial University.

The Canadian Collaborative Group for the Prevention of Renal
and Cardiovascular Endpoints Trial (CanPREVENT) involves five
centres across Canada, with St. John’s as the coordinating
centre. The principal investigator is nephrologist Dr. Brendan
Barrett, professor of Medicine at Memorial.

“We wanted to do something significant in nephrology
clinical research,” said Dr. Barrett. “Initially
we thought we’d be able to do a full-scale trial within
Canada, but it became fairly clear that to achieve this might
require partnership with sites in the United States.”

Dr. Barrett said the initial idea for an $11 million trial
over five years on up to 4,000 kidney patients was scaled
back to a two-year pilot study with 500 patients in Canada
alone.

“What we’re rolling out this month, which is Kidney
Month, is a vanguard pilot study that will be the beginning
of a full-scale study,” he said. “The same patients
can remain in the full trial and we can enrol others if it
looks like we’re meeting our recruitment and other interim
study targets.”

While many people think of dialysis as a treatment for kidney
disease, Dr. Barrett said that a greater majority of people
who have low kidney function actually die of something else,
including heart disease.
“Controlling blood pressure and other factors is very
important because we know it’s extremely relevant to
the way in which kidney and cardiovascular disease gets worse.”

There are many reasons why people get kidney disease, but
the growing rate is tied in part to the increase in diabetes.
“Over time about one-third of people with diabetes will
end up with kidney damage and some will go on to advanced
kidney failure. On top of that there is high blood pressure,
blood vessel diseases that can affect blood flow to the kidneys,
inflammatory kidney diseases and hereditary disorders.”

The pilot study will recruit 100 patients per site in five
sites across Canada. “We’re not particularly looking
to recruit people known to us with kidney disease,”
said Dr. Barrett. “What we’re trying to find out
is whether people who have chronic kidney disease of moderate
severity can be managed more effectively than currently happens,
and for that we need to identify people who don’t necessarily
know they’ve got chronic kidney disease, or at lest
to include some such people.”

Care for people with kidney disease can range from those who
receive no treatment because they don’t know they have
a problem, to others who know it and are being treated by
their family doctor, through to those who are seeing a specialist.
“In recruiting people for this study we will take advantage
of electronic health records,” explained Dr. Barrett.
“When a person has blood work done, a record is kept
at the hospital. Without us knowing who any individual is,
we can have the lab prompt the physician who ordered the blood
test if the results are within a certain range that are of
interest to us. We let the doctor know that he or she can
discuss the possibility with the patient of enrolling in the
study. This method preserves privacy and confidentiality and
it’s the doctor’s choice to let the patient know
about the study or not.”

For practical reasons, kidney patients in the Newfoundland
part of the study will need to live in the Avalon Peninsula
area. “Part of treating kidney patients is to bring
their blood pressure down and that may mean seeing them every
week or every month. The minimum we need in terms of doing
measurements for the study is to see each person in the study
every three to four months.”

Dr. Barrett said it is not a trivial matter to measure the
intervention being applied in the study. “For example,
we’re not using just one drug to lower drug pressure.
We’re doing a whole series of interventions including
the way the nurse works with the patients, the way the patient
gets involved in their own care, the way their family helps
them, how the nurse and doctor work together and how they
deal with the study protocol.”

The CanPREVENT study will compare usual care with a nurse-coordinated
multi-risk factor intervention clinic involving a nephrologist,
and applying known treatments to reduce or delay the onset
of advanced kidney disease and heart and blood vessel problems
such as heart attack, stroke and death. The study will also
address issues of costs associated with care and illness.

The pilot study is funded by $1.25 million from the CIHR New
Emerging Teams Chronic Disease Management Program, which includes
the CIHR Institute for Diabetes and Metabolism, the CIHR Institute
of Circulatory Health, the Kidney Foundation of Canada, Heart
and Stroke Foundation of Canada, Canadian Diabetes Association
and as well $750,000 from the biotechnology company Amgen,
$750,000 from Ortho-Biotech and $300,000 from Merck-Frosst
Canada.